Später beschreibt der Student die Ursache seines Fehlers in einem kurzen Text.

Later the student describes the cause of his mistake in a short text.

Breakdown of Später beschreibt der Student die Ursache seines Fehlers in einem kurzen Text.

• in: in
• später: later
• sein: his
• kurz: short
• der Student: the student
• der Fehler: the mistake
• die Ursache: the cause
• beschreiben: to describe
• der Text: the text

Questions & Answers about Später beschreibt der Student die Ursache seines Fehlers in einem kurzen Text.

Why is Später placed at the beginning of the sentence, and why does beschreibt follow immediately after?

German main clauses follow the “V2 rule” (verb-second). When you start with something other than the subject (here the adverb Später), the finite verb must occupy the second position. The order is:
• Später (adverb)
• beschreibt (finite verb)
• der Student (subject)
This is different from English, which normally stays S‑V‑O regardless of fronted adverbials.

Why is der Student and not den Student or dem Student?

der Student is the subject, so it’s in the nominative case.
• Nominative masculine singular = der Student
• Accusative masculine singular = den Student (for direct objects)
• Dative masculine singular = dem Student (for indirect objects)
Since der Student does the action (he describes), you must use the nominative.

Why is die Ursache used here, and how do I know it’s accusative?

The verb beschreiben (to describe) takes a direct object in the accusative case. Ursache is a feminine noun:
• Feminine nominative = die Ursache
• Feminine accusative = die Ursache (same form)
Because the cause is what’s being described, it’s the direct (accusative) object, so you see die Ursache.

What does seines Fehlers mean, and why is it in the genitive case?

seines Fehlers = “of his mistake.” This is a genitive attribute showing possession/relationship.

1. Fehler (mistake) is masculine singular. In genitive it takes -s → des Fehlers.
2. The possessive pronoun sein in genitive masculine singular becomes seines.
   Put together: seines Fehlers = “of his mistake.”

Why is the phrase in einem kurzen Text in the dative case rather than accusative?

The preposition in governs dative when indicating location (“in” = static), and accusative when indicating movement into something. Here the description happens inside a text (location), so we use dative:
• Masculine dative singular article = einem
• The adjective kurz takes the mixed‑declension dative ending -en after einem → kurzen
Hence in einem kurzen Text.

Why does the adjective kurz get the ending -en here?

After an indefinite article (einem) in the dative singular, adjectives always take -en (mixed declension):
• in + dative → in einem
• kurz → kurzen
So you get in einem kurzen Text.

Could you ever say in einen kurzen Text instead?

Only if you meant movement into the text (which is unusual). That would force accusative: in einen kurzen Text. But since the sentence describes where the writing takes place (no motion), you must use the dative form in einem kurzen Text.